I have recently upgraded OS systems on my desktop to windows 7 but at the moment internet speeds are really slow. I then reverted back to vista and my internet seems to be really fast. What is the problem? Please help!

When i’m on the internet my computer screen blinks (vista acer) and i use the normal internet. I don’t know why it does it and

How can i stop it?

Or disable the entire internet security?
i’m using norton 360.3 for my protection.

I understand that this is a virus and i was wondering how to completely remove it?

Every time i load up the internet, i get redirected into buying this software to remove the viruses. When i run windows defender it says there are 30 infections. I get a constant pop up of threats and keep being told to purchase the vista smart security in order to remove all of the viruses.

How do i completely remove this virus?

Thanks